Liebert UPS

A home standby electrical generator takes about 30 seconds to take over when utility power fails. An Uninterruptible Power Supply (UPS) can bridge that 30 seconds to protect crucial loads. Computers and home theater equipment are sensitive to power surges and outages. There are two things to consider when choosing a UPS, the capacity and the run time. Centralizing the UPS on a new house avoids having to buy and place multiple small UPSs around the house. At this home, a 6KVA Liebert GXT2-6000RT208 UPS was selected. It has a run time of about 5 minutes at full load. Five minutes is plenty of time when a standby generator is available. The photo below links to several installation photos.

A separate breaker panel was installed and the UPS was located in the telecommunications room. The construction electrician wired receptacles back to the UPS panel. Each television, home theater and computer location was fed from the UPS panel. Junction boxes were wired in the telecommunications room so the UPS could be wired in between the generator breaker panel and the UPS panel. SO cable was used to connect the UPS to the junction boxes. Click the diagram below to see the generator and UPS interconnections.

The Liebert UPS has an option for an Ethernet interface to monitor and configure the UPS via a web browser. This option was included and provides a dynamic status page with load and status displays. Additionally the UPS has digital outputs. The outputs were wired to the USB Data Acquisition Computer. The outputs indicate the status of the UPS input power source and the UPS battery condition. The Data Acquisition Computer generates a web page similar to the following:

Utility:	On
Generator:	Stopped
ATS:	Utility Position
Panel:	On
UPS Input:	On
UPS Battery:	Normal

The 6KVA UPS is plenty for three HD TVs, three computer locations and a Home Theater system. The UPS is loaded less than 10% so it doesn't have any trouble holding the load until the generator starts. Besides provding power, the UPS is an excellent surge protector. This Liebert UPS is always on. It is not like most low cost small UPSs. This one runs the load off the batteries all the time instead of switching to batteries when the supply fails. The UPS also produces a true sine wave instead of the typical square wave.